Although scientists are reluctant to endorse green tea as a cancer prevention method, evidence continues to grow regarding the chemically complex drink’s potential benefits - including results of a new randomized, controlled trial by researchers at University of Texas M. D. Anderson Cancer Center, which suggest it had some inhibiting effect in patients with a pre-malignant condition known as oral leukoplakia.

As reported in a report published online Nov 5 by Cancer Prevention Research(1), a team headed by Vassiliki Papadimitrakopoulo, MD, professor of medicine in M.D. Anderson’s Department of Thoracic/Head and Neck Medical Oncology, tested green tea extract taken orally for three months by 41 patients diagnosed with oral leukoplakia and therefore at high risk of developing oral cancer.

The patients were divided into cohorts taking either placebo or one of three different doses of green tea extract 500 mg/m2, 750 mg/m2 or 1,000 mg/m2 [mg/m2 refers to milligrams per meter squared of body mass – calculated by a formula using height and weight to reflect a person’s relative size].

• And a trend towards improvement in a handful of biomarkers that may be important in predicting cancer development.

Patients were followed for 27.5 months and at the end of the study period, 15 developed oral cancer.

• Although there was no difference in oral cancer development overall between those who took green tea and those who did not,

• Patients who presented with mild to moderate dysplasia [abnormal cell growth] had a longer time to develop oral cancer if they took green tea extract.

Although encouraged by the results, Dr. Papadimitrakopoulo cautioned against any recommendations that green tea could definitely prevent cancer.

“This is a phase II study with a very limited number of patients who took what would be the equivalent of drinking eight to 10 cups of green tea every single day,” she said. “We cannot with certainty claim prevention benefits from a trial this size.”

Dong Shin, MD, (professor of hematology and medical oncology at Emory School of Medicine, and a Cancer Prevention Research editorial board member) agreed, but said this trial is certainly a step in the right direction. “A clinical trial with a natural compound is no easy task, and these researchers have accomplished that,” Dr. Shin stated in a companion article commenting on the trial(2). “The lack of toxicity is also important because often when you give supplements at higher doses than what would occur naturally, you induce nausea and vomiting. That did not happen in this trial.”

Neither researcher had a reason why patients concerned about cancer should not drink green tea, but they cautioned against relying on the beverage to definitively reduce their risk of cancer.

Note: This information has not been evaluated by the FDA. It is general and is not meant to prevent, diagnose, treat or cure any illness, condition, or disease. It is very important that you make no change in your healthcare plan or health support regimen without researching and discussing it in collaboration with your professional healthcare team.